Genetic disorders caused by abnormalities in the number and structure of chromosomes are called “chromosomal disorders,” or chromosomal abnormality syndromes. Due to the different chromosomes, there are autosomal abnormalities and sex chromosomal abnormalities. The former can cause morphological and functional abnormalities of the body or organs, such as congenital mental retardation, developmental delay and multiple malformations; the latter can cause abnormal gender differentiation of the patient, with clinical manifestations such as hypogonadism, mental retardation and multiple malformations. Clinically, for infants or children, chromosomal examination is recommended if abnormalities such as multiple malformations, growth retardation, mental retardation, and blurred external genital differentiation (e.g., pubic menstruation with hypospadias, pubic emperor hypertrophy in the form of a penis) are found. In adolescent girls with abnormal secondary sexual characteristics, absence of menstruation, sexual dysplasia (infantile uterus or absence of uterus), short body, elbow ectropion, shield chest and slightly low intellectual development, little or no pubic and axillary hair, low posterior hairline, etc., should be considered for X chromosome abnormalities (Turner’s syndrome, karyotype 45, XO). In males with abnormal secondary sex characteristics, small testes, poorly developed laryngeal nodes, scant pubic and axillary hair, fine skin, and fine voice, the possibility of Kerner’s syndrome (47, XXY) should be considered. About 7-10% of couples with fertility disorders such as infertility, recurrent miscarriages and malformations are carriers of chromosomal abnormalities. Common structural chromosomal abnormalities are balanced translocations, inversions and numerical abnormalities (45, XO or 47, XXY). Balanced translocations and inversions have no gene loss and the carriers themselves are mostly free of abnormalities, but the reorganization of chromosomes during the formation of their germ cells can lead to abnormalities in the sperm or eggs resulting in infertility, miscarriage, abnormalities, stillbirths and other abnormalities. Premarital or preconception chromosome testing can help detect these conditions.